<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>flex 画骰子</title>
  <style type="text/css">
  .box {
    width: 200px;
    height: 200px;
    border: 2px solid #ccc;
    border-radius: 10px;
    padding: 20px;
    display: flex;
    justify-content: space-between;
  }

  .item {
    display: block;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: red;
  }

  .item:nth-child(2) {
    align-self: center;
  }

  .item:nth-child(3) {
    align-self: flex-end;
  }

  </style>
</head>
<body>
<div class="box">
  <span class="item"></span>
  <span class="item"></span>
  <span class="item"></span>
</div>
</body>
</html>
